mmbio 222 quiz 2 review

Grain stain procedure

1. Prepare smear

2. Crystal Violet (1 minute) + rinse

3. Iodine (1 minute) + rinse

4. Decolorize (3 seconds) + rinse

5. Counterstain (safranin) (1 minute) + rinse

6. Dry

• (gram + = purple) (gram - = pink)

liquid culture procedure

• just apply to slide with inoculating loop and heat fix through flame

solid culture procedure

• add a drop of di water to slide and used inoculating loop and mix solid culture with water. heat fix through flame

capsule definition

• additional covering around the outside of the cell

capsule composition

polysaccharides

capsule purpose

• enhance virulence (severity of a disease) and makes them more resistant to phagocytes and other threats

stains in a gram stain

• Primary Stain —> Crystal Violet

• Mordant —> Iodine

• Decolorizer —> Acetone

• Counterstain —> Safranin

endospores definition

• oval, metabolically inactive structure formed within the bacterial vegetative cell

endospores properties

• very resistant to drying, freezing, UV light, heat, and chemicals

Genera that produce endospores

• Bacillus (gram +, aerobic rods)

• Clostridium (gram - , anaerobic rods)

acid fast cell definition

• Definition: cells that resist stain entering and exiting the cell because of a waxy lipid covering the membrane (mycolic acid)

• One genus is mycobacterium

acid fast vs non acid fast procedure

1. Primary Stain (carbon fuchsin)

2. Steam over water for 8 minutes to force stain into cells

3. Decolorize with acid alcohol (15-20 seconds) + rinse

4. Counter Stain (methylene blue) (30 seconds) + rinse

5. Dry

• (acid fast = red or pink) (non-acid fast = blue)